Two widely used types of brake systems for vehicles are drum brake systems and disc brake systems. Drum brakes work by pressing a brake shoe against the inside circumferential surface of a wheel rim to retard rotation of the wheel. In a disc brake system, rotation of a brake disc or brake rotor mounted on the vehicle's axle is retarded when a caliper presses a pair of brake pads against opposite sides of a rotating brake rotor. Drum brake systems are not as effective and are more prone to failure and wear than disc brake systems, therefore, it would be especially advantageous to be able to replace existing drum brake systems with disc brake systems. However, vehicles with drum brakes impose constraints on the size and design of any replacement disc brakes that may be used since the entire disc brake must be housed within the wheel rim. With current disc brake systems, the wheel rim constrains the diameter of the brake rotor to an inefficient size since a large amount of space must be left around the rotor to accommodate the caliper.
Thus, there is a need in the art for a disc brake system that can be used both in the construction of new vehicles and in the retrofitting of existing vehicles.